You can go to Event Espresso > Transactions, then input a “From” date and a “To” date, then click the Filter button. That will give you a list of transactions between the dates.
With regards to deleting registrations, you can click the screen options tab on the Event Espresso > Registrations page and set the Pagination to 100 registrations per page. Then you can select “Incomplete” then click filter. This will filter the list to show only Incomplete registrations where you can check the checkbox at the top left corner of the list table, then select Trash Registrations, then click Apply. This will trash registrations by the 100, and you can repeat the above for Pending Payment registrations if you so desire.